Overall Image Quality

I was very impressed by the Digital IXUS 300, it's a tiny
little package which can deliver the goods just like it's bigger counterparts.
Resolution was very good, as was (in natural light) white balance, images
exhibited very little noise, indeed up close gradients were smooth and
clean with very little noise"speckle". The IXUS 300 had a tendency
to overexpose in certain circumstances, generally an exposure compensation
of -0.3 EV when shooting outdoors counteracted this metering curiosity.
Some people may find the images a little soft, but it's clear that Canon's
new philosophy of leaving the sharpening decision to the photographer
in the digital darkroom has made its way into the IXUS 300's design.

Maintaining shadow detail

Original image, good for printing, shadow
detail maintained

Contrast adjusted image, perfect for
the monitor, less ideal for printing

Something else inherited from the G1/Pro90 is the attempt
to maintain as much shadow detail as possible by maintaining the dark
end of the grayscale at about 10%, this means that no dark detail gets
clipped by over enthusiastic contrast algorithms, this leads to a neutrally
balanced and fairly "flat" image.. This balance of image works
perfectly for printing, indeed some of the thought process behind it may
be to do with Canon's new direct-connect printers, but mostly I think
it's just to maintain detail were it would normally be clipped. Obviously
this means that if you want your images to have real contrast (black is
black) you'll need to do a little level correction on some of them (Photoshop;
Image > Adjust > Auto Contrast; will do this fairly well).

Colour saturation

Original image, low contrast, low saturation

Contrast corrected, saturation boosted
+15

One area of disappointment for me were slightly pale colours
(low saturation), to give the image the zing (colour "punch")
it deserved I nearly always had to push up the colour saturation of an
image by about +15 (Photoshop; Image > Adjust > Hue/Saturation >
Saturation +15).

Purple Fringing (Chromatic Aberrations)

Surprisingly good news here! For such a tiny little lens
the IXUS 300 exhibited almost NO visible chromatic aberrations, yes it
suffers a little from blooming (the overflow of charge from saturated
pixels) which you can see below, but this shot taken with a camera with
chromatic aberrations would have large purple highlights around the branch
detail. Whether Canon are doing this through post-processing or its down
to the lens / sensor design is inconsequential we have to give some Kudos
to Canon for virtually eliminating one of our biggest complaints.

Visible chromatic aberrations in an
"every day shot"

Our now standard chromatic
aberration test shot *

* I'm not totally happy with this shot, it's the best one we got, unfortunately
the IXUS 300 simply didn't want to focus on our completely black test
chart let alone produce an effective +2.0 EV overexposure, so please don't
use this image as reference against another result.

Barrel and Pincushion Distortion

Zero, no pincushion distortion at full tele, another excellent
achievement from such a small lens. There is however visible barrel distortion
at full wide angle, we measured it as about 1.1%.

Barrel Distortion, 1.1% @ Wide Angle

Pincushion Distortion, 0.8% @ Full
Tele

White Balance

Good news, white balance presets which actually work!
Once more Canon seem to have solved another niggling problem, white balance
presets which don't quite work, the sunny, indoor and fluorescent presets
work well and should get you out of trouble even in odd lighting conditions.
The Auto white balance only seemed to work well in natural light.